File upload with Sinatra

Ethan Turkeltaub picture Ethan Turkeltaub · Apr 21, 2010 · Viewed 22.6k times · Source

I am trying to be able to upload files with Sinatra. I have the code here, but I'm getting the error "method file_hash does not exist" (see /lib/mvc/helpers/helpers.rb).

What is going on here? Is there some dependency I'm missing.

Answer

Jeremy Mullin picture Jeremy Mullin · Feb 27, 2011

I've had good luck with the example code found on this thread.

Including it here in case the link ever disappears:

post '/upload' do
  unless params[:file] &&
         (tmpfile = params[:file][:tempfile]) &&
         (name = params[:file][:filename])
    @error = "No file selected"
    return haml(:upload)
  end
  STDERR.puts "Uploading file, original name #{name.inspect}"
  while blk = tmpfile.read(65536)
    # here you would write it to its final location
    STDERR.puts blk.inspect
  end
  "Upload complete"
end

Then your view would look like this. This uses HAML, but the important part is not to forget to set the enctype in your form element, otherwise you will just get the filename instead of an object:

%form{:action=>"/upload",:method=>"post"   ,:enctype=>"multipart/form-data"}
  %input{:type=>"file",:name=>"file"}
  %input{:type=>"submit",:value=>"Upload"}